For largely technical reasons, Session Initiation Protocol (SIP) has been evolving from signaling directly between user agents to signaling through proxies. Session Border Controllers (SBCs) may be utilized on network borders to police the media traffic that enters a network and, through its normal operation, may obscure information regarding endpoints. In operation, an SBC may modify the one or more fields of a message transmitted through the SBC. For example, an SBC may modify a message's Internet Protocol (IP) addresses or ports.